I agree with everything you're saying. I just want to point out some caveats to trains (although I absolutely love them and prefer them to cars or planes as well). The obvious one is that few people have enough vacation days to spend multiple days traveling by train. Even if we aren't talking about paid vacation, not every job/position lets you take unpaid time off. Some jobs don't let you take more than one or two weeks in a row.

For families this can be additionally challenging since a lot of vacation days need to be taken when school or daycare is out, or the kid is sick, or the kid needs to go to some dentist appointment, leaving you with a total of a week of vacation.

Yeah, and kids in general. It is difficult to keep little children, who want to move and be loud, on a train for days. It's not impossible, but most likely everyone will be a nerve wreck by the time of arrival. The other people on the train will hate you because you cannot "tame" your kid, or they will judge you because after one and a half days you decide to allow your kid to watch a movie on a tablet to have a break. The relaxing aspect of a train ride tends to vanish.

And last but not least, health conditions. Some people cannot sit for long periods of time and have to wear compression socks or even get heparin shots to prevent thrombosis. This is already the case for a 6 hour flight, but 6 days of minimal movement is difficult and not recommended. You can do it - there are ways to do it - but it is something that you need to keep in mind when travelling.

But nevertheless, I agree that long train rides and a break from the fast paced, information immersed world is great. Maybe this: as long as you can do so, do it! There might be a time in your life when this will be more difficult and you will have to pause and find a better suited alternative. But that doesn't mean you can't unpause when the time is right. Enjoy!